The present invention relates generally to metal enclosures, and more particularly, to a meter socket enclosure, such as for use in watt-hour meter sockets. This type of socket is known in the trade as an “S” type meter socket. The dimensions of such enclosures are determined by various factors. The width of the enclosure must be wide enough to accept a conventional watt-hour meter and any utility or customer wiring cable that may need to pass along the side of the meter socket. The length of the enclosure must also be able to accept the watt-hour meter and must also provide sufficient “wire-bending” space as required for installation or by regulating agencies, such as Underwriters' Laboratories, Inc. The depth of the enclosure must accept the meter socket assembly components and be deep enough to provide sufficient space for the conduit used to protect the utility and customer wires and the locknuts used to secure these conduits. To minimize tooling costs, manufacturers typically standardize on the meter socket assembly components used for sockets of various ampere ratings, such as 100 ampere and 200 ampere sockets. Electric codes and standards specify wire size requirements and also the conduit sizes required for these ampere ratings. As a direct consequence of the aforementioned constraints, 100 ampere and 200 ampere meter sockets are usually of the same width, but may be a different length (to allow for the wire bending requirements) and a different depth to allow for the differing conduit requirements.
In prior art, the meter jaw assemblies are constructed so that they fit in the minimum height required for 100 amp conduit trade size of 2 inches (5.08 cm). When the same meter jaw assemblies are used in a 200 ampere meter socket enclosure, which requires a 2.5 inches (6.35 cm) trade size conduit, additional components are employed to raise the meter jaw assemblies to the correct height to receive the watt-hour meter. This additional height is approximately 0.75 to 0.875 inch (1.91-2.22 cm) in most modern designs.
FIGS. 1 and 2 show internal components of a typical modern 200 ampere enclosure 100. Meter jaw assemblies 102 are attached to a riser or bridge 106 that provides the proper mounting height or spacing from a back wall 110 of the enclosure 100. Mounting screws 114 attach the bridge 106 to the back wall 110 enclosure 100. Mounting holes and optional dimple features (not shown) may be provided to mount the bridge 106 and meter jaw assemblies 102. FIG. 1 shows a view of the mounting bridge 106 having 118 to engage the holes or dimples and holes 122, such as the slotted holes illustrated, to permit fastening with the screws 114 to the enclosure back wall 110. Also shown are extruded holes 126 which may be tapped to allow the fastening of the meter jaw assemblies 102 to the bridge 106. Additional features of conventional meter socket enclosures, mounting bridges 106, and meter jaw assemblies can be found in U.S. patent application Ser. No. 11/849,708, which is incorporated herein by reference.
The illustrated bridge 106 includes laterally spaced mounting walls 130 on which the meter jaw assemblies 102 are secured, as by fasteners or screws 132. The extruded holes 126 may be formed in the mounting walls to receive the screws 132. The holes 126 are spaced in such a manner as to provide the proper spacing between transverse sets of meter socket jaws 136 to receive connector blades of a standard watt-hour meter (not shown). The mounting walls 130 are separated by a recessed wall 140, which may be used to mounting a grounding conductor connector (not shown). The illustrated bridge 106 is provided with laterally spaced mounting flanges 142 having the holes 118 and 122 formed therein for mounting to the back wall 110 of the enclosure 100.
The prior art construction described above has disadvantages. Firstly, the use of additional components acts to increase both material and labor costs. Secondly, the bridge component contributes to reduced stability of the meter mounting position, both on initial positioning and in resistance to side loading forces.